Commentary by Pigini

PPC Insulators

High Voltage Insulator Coatings: State-of-the-Art & Future Development

A HVIC Symposium organized by the Gulf Co-operation Council Interconnection Authority (GCCIA) was held in Dammam, Saudi Arabia this past February. Following upon an earlier such Symposium organized in Avellino, Italy last October, this next event again... Read More

Testing Adapts to UHV

Evolving HV Testing Adapts to UHV

High voltage testing has undergone remarkable evolution over the past 100 or so years and new technologies are imposing the need for continuing adaptation. Looking back at the earliest days of transmission, insulators and electrical equipment were verified... Read More

Insulator Performance Under Ice & Snow

Flashover problems encountered across the globe confirm that ice and snow can significantly diminish insulator performance and impact grid reliability. Much research has therefore been published on this topic and an excellent review was made by Masoud... Read More

Assessing EHV & UHV Station Post Insulators

Developments in station post insulator technologies can help minimize arcing distances needed at busbars, disconnectors and similar apparatus and therefore contribute to more flexible substation design. In general, station posts can be optimized by using... Read More

Insulator Failures from Improper Selection

At a past CIGRE meeting in Paris and in particular during the Study Committee B2 session on Overhead Lines, there was much discussion on the still debated issue of the ‘stateof- the-art’ of composite insulator technology. A spectrum of contradictory case... Read More

Dielectric Strength & Air Density

While a number of atmospheric parameters affect the dielectric strength of external insulation, relative air density (δ) and absolute humidity are considered the most significant. Here, the focus is on the former, which plays a key role in developing... Read More

External Insulation Under Composite AC Plus DC Voltages

Growing interest in parallel routing of AC and DC circuits on the same towers of what are referred to as ‘hybrid overhead lines’ could cause both AC and DC voltage components (known as composite voltages) to appear on line insulators. Up to now, knowledge... Read More